strange zpool status output

[Matt Burke]

On 07/12/11 18:38, Freddie Cash wrote:
> On Tue, Jul 12, 2011 at 5:22 AM, Steven Hartland <killing at multiplay.co.uk>wrote:
>> scrub: scrub in progress for 307445734561825859h27m, 6.96% done,
>> 307445734561825849h8m to go
> 
> Nothing odd.  It takes a good 15 minutes or so for the scrub code to
> determine just how fast things are going, how much work there is to do, etc
> etc, before the progress line makes sense.  The "time in progress" and "time
> to go" numbers will fluctuate rapidly for the first little while, and then
> settle down into "normal" numbers.

Why would "time in progress" fluctuate? It's simply (now-start)...

I'd guess the system time's gone back since the scrub started.